Rectifier Tube Blown. Weird Behaviour?

[paulg2uk]

Hey guys,

So I had a bit of a problem with my Mark V this evening at rehearsal. I plugged everything in powered up my mark v and connected my pedalboard etc. I was talking to my singer and then as I turned around to switch the amp out of standby I noticed it had turn itself off. I checked my power cable which was fine and then thought I should check the fuse. The fuse had indeed blown. At this point I'm thinking a power tube possibly. Anyway's I had some spare fuses which I put back in and switched the mark v back on. It all seemed fine and nothing had blown. I am now a bit confused why the fuse had blown.

I didn't think anymore of it and the band began to rehearse. The first few songs were all clean tones which sounded good to me. It wasn't until we moved onto the more drive based tones I noticed the amp on both chan 2 and 3 were pretty loud but lacking a bit of drive to them. My setting had remained the same before this problem and there is more than enough drive normally for me. Another thing that I noticed my master volume was just below half way and I usually set my solo control just above which is more than enough for me and to cut through the band. When the solo control was engaged for a solo I noticed there was a slight increase in volume but no way enough than I usually have.

I knew something wasn't right but played on anyway. We finally had a break and I decided to take a look at the tubes. All the power tubes were powered up and were glowing ok and that's when i noticed the rectifier tube wasn't glowing at all. I felt it and it was stone cold so it hadn't been working all along. I'm a bit confused because if the rectifier tube is dead wouldn't the mark v still be blowing fuses? What do you guys think? Obviously I need a new rectifier tube. But don't you think it's weird behaviour? Or am I total wrong?


I should add that I recently change both sets of power tubes and the v7 preamp as well.

Many thanks

Paul

 

[LesPaul70]

Did you check that the rectifier tube was not simply loose and not getting any contact? A car ride could shake the tube loose if it is not properly tightened.

What wattage settings were you using? 90W is always silicon diode rectification, 45W is choosable, and 10W is always tube rectification.

 

[paulg2uk]

Did you check that the rectifier tube was not simply loose and not getting any contact? A car ride could shake the tube loose if it is not properly tightened.

What wattage settings were you using? 90W is always silicon diode rectification, 45W is choosable, and 10W is always tube rectification.

Everything is set to 90 watts and I did check to see if the tube was loose and it seemed fine.

I got an email back from Tien as boogie this morning. He said its possible that because the amp is set to 90 watts on all channels the amp could still work without the rectifier tube. and the tube blowing has made it sound unusual. Which makes total sense to me.

Just typical that the tube that blows is the one I didn't buy as a spare. I've ordered a replacement and a spare anyway will see what happens when i receive it.

 

[boogieman60]

I broke my rec. tube taking the FS switch out of the pouch. The amp would not work properly all the levels were messed up and the sound was awful. I think it is a myth that if its "not in the circuit " it should work..Mine didn't. Must have something to do with the voltage...